POLLEN-BODIES OF THE ANGIOSPERMS. 
19 
Studies on the Pollen-Bodies q/ Angiosperms. By 
Fred. Elfving, of Helsingfors. ^ Y/ith Plate IV. 
Until very recently botanists believed it to be a well- 
established fact that the Pollen-bodies of the Angiosperms 
were one-celled, that when once formed as tetrades in the 
pollen mother-cell they underwent no further divisions. 
This was thought, too, to form a direct contrast with the 
Pollen-bodies of the Gymnosperms, in which, as is well 
known, shortly before the period of pollination, one or more 
so called vegetative cells are formed, which are regarded as 
constituting a rudimentary male prothallus. 
Strasburger^ has, however, quite recently shown that the 
Pollen-bodies of several Angiosperms, both Mono- as well as 
Di-cotyledons, possess two nuclei ; he has further shown 
that one of these originally pertained to a small peripherally- 
formed cell, and that it only became free by the subsequent 
resolution of the partition wall ; so that here, as in the case 
of the Gym.nosperms, a vegetative cell is formed in the Pollen- 
body. 
Strasburger further discovered in the case of the Orchideee, 
which he examined, that the nucleus of the large cell is 
always in front in the Pollen-tube. 
Strasburger points out that Reichenbach had already 
figured and described both nuclei in the Pollen-bodies of 
some Orchids ; and that Hartig had also rendered the two 
nuclei visible in the Pollen-bodies of several plants by the 
use of a carmine solution. Yet these notices, because they 
lay somewhat out of the beaten track, remained almost un- 
observed. 
I have attempted, at the request of Professor Strasburger, 
to continue the researches into the stages of development of 
the Pollen-bodies of the Angiosperms. My researches, with 
this view, were made in the summer time of 1878 in the 
Botanical Institute at Jena, under the direction of Professor 
Strasburger; and this paper contains the result. In these 
researches I had the advantage of Professor StrasburgePs 
very kind and able help; and I now gladly seize the oppor- 
tunity of expressing my warmest thanks to him therefore. 
My task consisted on the one hand in following up the 
^ Translated and condensed from the ‘ Jenaische Zeitschr.,’ 1879, 
part 1. 
^ “ Ueber Befruchlung und Zelltlieilung,” ‘Jenaische Zeitsclirift fiir 
Naturwissenschaft,’ Bd. xi, Neue Edge Bd. iv, 1877, Heft. 4, p. 450. 
